Vapor electric apparatus.



P. H. THOMAS.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED DEC. 6, 1911.

1 1 1 9 Patented Sept. 15, 1914.

2 SHEETS-SHEET 1.

Ill/VE/VTOR A770 IVEY P. H. THOMAS.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED me. e, 1911.

1,1 10,600, Patented Sept. 15, 1914.,

2 sums-SHEET 2.

64% a ATTOR/V V UNITED STATES PATENT OFFICE.

rnnc'r H. THOMAS, or Urrna MONTCLAIR, NEW JERSEY, ASSIGNOR TO COOPER HEWITT ELECTRII IC (30., OF HOBOKEIT, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent. Application filed December 6,1911. Serial No. 664,169.

4 VAPOR ELECTRIC AP-PARATUS.

. Patented Sept. 15, 1914.

To all whom it may concern Be it known that I, PERCY H. THOMAS, a citizen of the United States and resident of Upper Montclair, county of Essex, State of New Jersey, have invented certain new and useful Improvements in VaporElectric paratus, of which the following is a speci cation. 1

My invention relates to the operation of vapor electric apparatus, for example mercury vapor tubes utilized for the purpose of rectifying current from an alternating source. These tubes are well known in the electric art'and are characterized by a cont ainer supplied with one or more anodes and a cathode, usually of some such material as mercury which will vaporize during operation, giving a vapor which can condense and run back to the cathode and coalesce therewith. This is commonly known as a vaporizable reconstructing cathode. The container is exhausted to a high degree of exhaustion. In the ractical manufacture of. such devices it is foundinconven ient to get absolute perfection of vacuum in all cases and the harmful effects of these extremely minute traces of foreign gases may be serious if not controlled.

The present invention has for one of its main objects the 'fortifying of the opera-.

tion of the device against such influences.

One of the principal effects of the presence of these gaseous impurities is the production of a tendency to weakenthe negative electrode starting reluctance of the anodes within the container which tends to cause occasional failure of the negative electrode starting reluctance of the anodes and permit an abnormal flow of current directly between the anodes which upsets the operation of the apparatus. The correct view of this action appears to be that the residual gases in the container are ionized by the flow of normal current. Such ionization would result in positively and negatively charged particles which would be attracted-respectively to the electrodes for the moment charged negatively and positively. The positively charged particles would thusbe naturally drawn to the non-operating anode where they would undoubtedly have the above mentioned weakening tendency on the negative electrode reluctance of the anode 'which has been actually observed.

' of glass.

a number of wa s, for example'by intercepting these partic es on their way to the main anodes and discharging them, thus removmg the force which tends to draw them to the main anodes. A method and apparatus for accomplishing this result is shown in the accompanying drawings to the description which reference may be had for a fuller explanation.

Figure 1 shows a rectifier-embodying. my invention in simple form and Fi 2 a modiiication thereof. Fig. 3 shows tie application of the invention to a three phase device. Fig. 4 shows a vertical section of Fig. 3 on the line a, 0:.

InFig. 1, I show an exhausted container at 1, the container in this case being made At 2 and 3 are main anodes of solid material, while 5 is the usual starting electrode. This rectifier is supplied from the winding 6 which may be a generator winding or the secondary of the transformer. At 7 is a reactance which may serve the'keeping alive function in the system and at 8 is a work circuit which may consist of any of the well known translating devices adapted to utilize rectified current. I have shown the main anode 4E and the startin electrode 5as of mercury. At 9 and 10 I show protecting anodes interposed in the path of charged particles whichmay be attracted to the corresponding main anode when the latter is impressed with a negative potential. As

shown these protecting anodesare rings of iron or graphite or other suitablemat'erial supported and connected by leading-in wires to the source 11 and 12 through the switches. These protecting anodes are energized in this particular case from the same supply as the main anodes but from a point of lower potential, namely the points 17 and 18 of the winding 6. I have shown impedances 13, 14, 15 and 16 in the leads of the several anodes for the purpose. of controlling the flow of current in their respective circuits. I have also shown a resistance, 29," connected between the main anode, 2, and the starting electrode, 5, which serves to control the starting current. The operation and at 4 is a main cathode,

of this device is as follows. During normal running current flows alternately from anodes 2 and 8 to the cathode 4 through the work circuit, 8, the coil, 7 back to the source. If the conditions within the container are not lower t e perfect, there Will-be experienced an'accompanyin deleterious influence tending to negative electrode reluctance of the electrodes 2 and 3. This influence is subject to electric attraction. Such particles ar presumably originated somewhere in the p th..of the'normal current then momentarily passing from the other anode to the cathode, presumably usually near the cathode and .in passing from their point of origin to the anode, 2, for example, they must pass close to the protecting anode, 9, which being impressed with a negativepotentia will attract them to itself and cause their imprisonment or discharge. As the anode, 9, is energized at a lower potential than the anode, 2, there will not be the same tendency for'a short circuit to occur in the device, nor will the same harm result should such short circuit occur. By the presence of the impedance, 15, I greatly limit any flow of current which may occur from the anode 9 in case its starting circuit should fail. I may, for example, permit the normally directed flow of 1 to 3 amperes between the electrodes 9 and 10 and the oathode 4 under conditions such that any short circuit occurring between them would be traversed by a relatively small amount of current.

It may be noted that the anode, .2, in virtue of its higher voltage will tend to have an attraction for the deleterious particles superior to that of the electrode, 9,- but'this tendency will be overcome by the effect of the greater proximity of the anode, 9, to these particles as they approach the latter electrode on their way to the former. As a net result, therefore, the particles will never escape'the electrode, 9, and reach the electrode, 2.

In certain cases I prefer to open the switches, 11 and 12, in the leads to the protecting anodes and close the switches, 19 and 20, as a result of which'the protecting anodes are fed from the same supply ,points as the main anodes but are controlled as to their operation by the superior resistances, 15 and 16, in the leads of the protecting anodes.

In Fig. 2 I show a similar system of circuits and a rectifier embodying the same general principle, but with a modified structure which has a number of advantages appertaining thereto. The protecting electrodes 21 and 22 are here shown as consisting of coatings 21, 21 on the inside of the arms of the container, 1. They are, as.

shown, provided with leading-in wires and, if desired, the leading-in wires may be protected by mercury in the pockets, 40, 40. I

I1ave inclined-the arms of the container, 1,

downward to secure more complete protection of the electrode. The high temperature of the anodes will prevent the accumulation of mercury in the tubes. In this figure I excite the protecting anodes, 21 and 22, from a separate-transformer having a secondary, 26, and a primary, 27. This primary, 27, is fed fromthe main supply, although it might obviously be fed from any other supply in synchronism therewith. Where desired I may advance or retard the phase of the voltage'impressed upon the protecting anodes, 21 and 22 for the purpose of more positively deflecting the deleterious charges or emanations, or influences, whatever they may be called. This'I' have accomplished in the figure by the use of an inductance in shunt to the transformer primary, 27, accompanied with series resistance, 28. Other features of this figurewill be evident upon inspection of the drawing.

In Figs. 3 and 4 I show an adaptation of my invention to a three phase rectifier apparatus with a metal container. 32 is the container with a cover, 39, hermetically sealed. The interior of this container is.

divided on the bottom into three chambers by the partitions, 50, 50, 50 extending well upward in the vapor space. An additional central pocket, 49, of insulating material serves as a cathode chamber. This pocketis preferably high enough to rise above the partitions, 50, though this is not always necessary. Each chamber contains a main anode, 33, located preferably below the top of the partitions, 50, and for each main anode, 33, is provided a protecting anode, 34, of flattened ring form and shown located above the main anode-.- The electrodes are insulated and supported by tubes of insulating material 37 and 38, the stems being sealed by mercury seals orvother siutable seals asshown at 45. A body of mercury at the bottom of the container, partly within the pocket, 49, and shown in 48, serves as a cathode and receives condensed mercury through perforations in the wall of thepocket, 49, preferably under the level of the mercury 48.

This rectifier is supplied from a three phase source, 43, either transformer secondaries or a three phase generator having its neutral connection, -16, carried to the container, 32, by the conductor, 46, and having each of its'three main terminals connected to one main anode in the usual manner, as,

for example at 47. The protecting anodes are connected from a point of the lower potentials 1n the windings of the source as shown in Fig. 3 or fed through separate transformers as is shown for one of the protecting anodes in Fig. 4 at 4 1 and 42. When it is desired to advance or retard the phase of the electromotive force applied to the protecting anodes, a suitable earlier or later electromotive force from the supply-may be utilized for feedin this anode.

The operation 0 this system-will be "read-- ily understood in view of the knowledge of the art and what has already been stated with regard to the other figures. The structures shown provide for. chambers for the three anodes and force upon the various currents and other particles passing between the electrodes an indirect path and also secures the result that such particles must pass the protecting anode before they reach the main anode. By this arrangement Iv succeed in protecting the main anodes.

I have in this specification described. certain structures as embodying my invention, but I do not wish to be understood as limited to this specific structure, for any system showing equivalent elements producing the same result in practically the same way falls within my invention.

I claim as my invention:

1. In a vapor rectifier comprising an exhausted container, lateral tubes extending from said main container main anodes therein and a vaporizable cathode in said con tainer and protecting anodes interposed between said cathode and said main anodes in said tubes and means for energizing said protecting anodes from a circuit capable of supplying only a limited amount of energy.

2. In a system oi electrical distribution, the combination with an alternating source, a receiving circuit, a vapor rectifier comprising an exhausted container, main anodes and a cathode therein and connections from the terminals of said source to said anodes for securing the passage of a continuous current from said cathode through said work circuit to said supply, of an additional anode located between said main anode and said cathode and connections from an intermediate point of the source to said additional anode.

3. In a system of electrical distribution, the combination with an alternati source, a receiving circuit, a vapor recti er comprising an exhausted container, main anodes and a cathode therein and connections from the terminals of said source to said anodes and means for securing the passage of a continuous current from said cathode through said work circuit to said supply, of an additional anode connected between said main anodes and said cathode and connections from an intermediate point of the source to said additional anode and a current limiting device in the lead of said additional anode.

4. In a system of electrical distribution, the combination with a mercury vapor rectifier comprising an exhausted container, main anodes therein, located in tubular extensions of said container, a main cathode therein and supplemental anodes consisting of conducting coatings on the inside of said tubular extensions located between said anodes and said cathode but nearer said means for energizing the main anodes and means for energizing said supplemental anodes at a lower potential and means for varying the phase of said last named means.

6. A mercury vapor rectifier, comprising an exhausted container, main anodes and a cathode supplemental. anodes interposed between said cathode and said anodes, said supplemental anodes permitting the free passage of current thereby and havin their surfaces exposed to passing matter, w ereby electric charges may be withdrawn from said passing matter.

7. A mercury vapor rectifier comprising an exhausted-container, main anodes and a cathode supplemental anodes interposed between said cathode and said anodes, said supplemental anodes being provided with tubular openings traversed by any flow of matter passing from said cathode to a main anode.

Signed at New York in the county of New York and State of New York this 5th day of December A. D. 1911.

rnncr H. THOMAS.

Witnesses:

WM. H. CAPEL, Tnos. H. Brown. 

